export function file2img(f){
    return new Promise(resolve=>{
        const reader = new FileReader();
        reader.readAsDataURL(f);
        reader.onload = (e)=>{
            const img = document.createElement('img');
            img.src = e.target.result;
            img.width = 224;
            img.height = 224;
            img.onload = ()=>resolve(img)
        }
    })    
}